Replace the lightweight 16G, leak prone, 1 5/8" OEM up pipes on your 2017-2025 6.6L L5P Duramax equipped Chevrolet Silverado or GMC Sierra 2500 / 3500 HD truck with these heavy duty 11 gauge 2" Stainless up pipe kit. HD Stainless Bellows that will not crack and leak like OEM. Increase Turbo spool-up and decrease EGT's. This kit is for use with factory exhaust manifolds. - - Fully compatible with WCFab Billet Exhaust Manifolds (Part Number WCF100373). - - INCLUDES GASKETS! -NO Tuning required, bolt on! -Will fit on stock truck no other modifications or upgrades necessary! - - Replaces the following GM Part Numbers: 12688021, 12702943, 12681437, 12680270, 12681162, 12674813, 12681162, 12676611 - - Also fits 2019+ L5D Duramax (4500/5500/6500) Medium Duty Trucks.

• Fully TIG Welded 11 GA Stainless Steel Construction
• Heavy Duty 2" Passenger Side Up Pipe
• Heavy Duty 2" Driver Side Up Pipe
• Flows 26% Better than OEM
• Up Pipe Gaskets (4)
• NO TUNING REQUIRED
• Made in USA

This Part Fits: